Telephone-exchange system



F. M SLOUGH.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEC. 5, 1917.

1 A27, 1 70, Patented Aug. 29, 1922.

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INVENTOR QME AZ K FRANK M. sriooen or nocrres'rnn, new roan, assrsnon'ro THE srnomnna n cannson rnnnrnonn nannrscrunrns comment, orROCHESTER, NE roan, n conronarron or new roan.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. Patg t d A gg 1922 Application filedDecember 5, 1917. Serial No. 205,599.

To all whom it may concern:

Be it known that I, FRANK M. SLoUcH, a citizen of the United States,residing at Rochester, in the county of Monroe and State of New York,have invented certain new and useful Improvements in Telephone ExchangeSystems, of which the following is a full, clear, and concisedescription.

It has been a common practice in operating telephone switchboards todivide the same up into sections at each of which is located a multiplejack for each of the telephone lines, and at'some of these sectionsmultiply connected signal lamps have been used to indicate a calloriginating on the associated telephone line.

in such switchboards of the art, the lamps of the diiferent switchboardsections associated with the same telephone line operate simultaneouslyupon the initiation of a call by a subscriber on the line, and it oftenhappens that several operators will attempt to answer the same call.

It is an object of this invention to prevent much of this confusion andto provide for more efficient team work between the operators. 1,therefore, provide for each opcrators position a number of answeringjacks, and for each an associated line lamp. Line and cut-off relays arepermanently as sociated with the answering lamp and answering jack tocontrol the operation of this lamp. T he number of answering jacks withtheir associated lamps provided for a position may vary, and may bebetween 100 and 200 in number.

The telephone lines leading into the switchboard preferably a "cpermanently associated with multiply connected switcl l board jackslocated each on a different section of the switchboard, and at one ormore of these switchboard jacks I provide multiple signal lamps. Now, bywhat is known in the art as cross-connecting, I may associate any linetogether with its connected multiple switchboard jacks and theirassociated signal lamps to an switchboard jack together with itsanswering signal lamp. What 1 term as the multiple jacks and theirassociated lamps of any line always therefore maintain a fixed positionin the switchboard, but as the crossconnection may be varied toassociate the said line with different answering jacks and answering"associated lamps variously located on the dnferent operators positions,such answerlng acks and lamps may not at all times be associated withthe same telephone line; also,

conversely the said telephone line may not always have the sameanswering jack and lamp, and it follows that since the line and cut-01frelays are permanently associated with the answering jack and lamp, themultlple lamps controlled by a given line and cut-off relay at one timemay be, by a different cross-connection, at another time controlled by adifferent line and cut-oil relay.

It has been a common practice in systems of the art operated under theabove plan to-occasionally cross-connect some of the lines, whereby anover-loaded position may have relief obtained through transferring "theanswering terminals and associated.

lamps of some of the busy lines to other positions. Although, this hasbeen of considerable benefit it is not always possible to accuratelygauge the number of calls originating on such a small group of lines asis associated with an operators posi tion, and much dependence istherefore had upon the operators at either side of an operator atemporarily over-loaded position reaching over and answering some of thecalls on such a position.

.-t is an object of my invention to char-.

acterize the signal indication given byany of the switchboard lamps toindicate the measure of the loaded. condition of the op erators positionwherein the lines with which these lamps are associated have theiranswering terminals. Thus, the operator observing calls on the positionsto, either side :an give assistance to the operator most in need of suchassistance, the character of the signal given by the lamps on each ofthese positions indicating the extent of the overloaded condition, ifany.

It is a further object of my invention to extend this over-load signalcharacterization to the multiply connectedlainps associated withmultiple jacks of a line which has its answering terminals in such anoverloaded position, whereby the operators at the switchboard sectionswherein these mul nals of lines having their answering terminals inrelatively busy or over-loaded positions. The characterization of signallamps above'referred to is variable, and the intensity of the signaldepends, directly in the system of my invention, to the degree ofover-load on the answering switchboard position.

v, I also provide means under the control of the operator at thedillerent positions to increase the intensity of the over-loadcharacterization of the'signals, so that the operator when attendingtheanswering of one call'will preferably, by the operation of her'operators telephone set connecting mecha nism herein illustrated asoperators listeningkeys, cause all or" the signals associated withcalling telephone lines on her position to indicatean additional measureof overload. My invention, therefore, is capable of being exercisedin'two forms, and each form maybe employed independent of orwith theother form. a

Other objects of my invention and the in vention itself will be betterunderstood from the description of the same which follows,

reference being had to the drawing accompanyingthis specification inwhich I show'at A and '13 two telephone stations comprising 'ahookswitch having contacts 0 and a telephone set 1", these beingconnected by line conductors leading to a mam telephone ex? change, thestation A being connected on a line L, and the station B being connectedon 'be made to the associated line when the said line is a called line,However, the multiple jacks CJB and CJA ofthe lines have associated withthem multiple lamps SLR and CLA, one signal lamp for each jack. Theselast-named Jacks are located on switchboard sections variously known inthe art as helping sections, concentration sections, or associatedswitchboard sections.

AtC, I show for the line L, what is known in the art as an intermediatecross-connecting rack on which the line may be crossconnected todifferent answering terminals.

The line L at C is cross-connected by means of conductors 37, 38, 39 and40 extending between terminals 25, 26, 27 and 28, to terminals 13, 14,15 and 16 to the. answering jackd having an answering signal lamp LB,and to the line and cut-oil relays asso ciated therewith 'LRB and COR.

Itis very desirable in the system of my invention that the line andcut-oil relays of the lines be permanently associated with the answeringterminals has been described,

rather than in accordance with the more common practiceof permanentlyassociating them with the multiple switchboard jacks and connected lineconductors. The reason for this is to preserve the propercharacterization or the lampsas will be described, regardless of thecross-connections which may be at the intermediate frame.

In this description it is assumed that the answering terminals of theline L and of the line L are located on the same operators position, andthat other lines not shown also terminate in like manner in thisoperators position, also that the multiply connected lamps and theirassociated multiple jacks of the lines leading into the exchange arevariously located on the multiple and concentration sections of theswitchboard, with or without regard to the location of their answeringterminals.

Inorder to better understand the invention I will now described thesame, referring to the operation of the apparatus involved in greaterdetail.

Assume that a subscriber on the line L makes a call to the GXClllIlgQllQwill take his receiver from the hook closing the contacts c of thehookswitch, place. his telephone set 7* in conversational circuit acrossthe line L which leads by its conductors and the cross connection wires35 and 36, to the call answering apparatus at the exchange.

The line conductors are continued by conductors 62 and 63 throughcontacts 58 and 59 to the line relay LRA which will now be energizedclosing its contacts 2 whereupon the line lamps associated with the linewill be lighted to give a signal. rill'o't the line lamps which arethree in number as shown in the embodiment in the drawing, will be sooperated over a circuit traced as follows: from the negative pole of thesource of current S to several branches of 'a dividedcircuit, eachleading to the conductor 54- one branch including the winding SR of adouble wound relay common to the operators position and a conductor 50,and another branch including a conductor 52- and a circuit interrupter Iwhich intermittently interrupts the circuit of the conductor 2, and thusintermittenly short circuits the winding SR of the double wound relay. Athird branch includes the resistance R together with circuit conductorsleading through contacts 71, 72 and 73 on the operators listoning keysof the position, whereby through the said key contacts the saidresistance is placed in multiple with the winding SR, and when theinterrupter I is not short circuiting the winding SR, the inclusion ofthisresistance coil in multiple circuit with the circuit SR modifies theeffect thereof in a man nor to be later described, this modificationbeing controllable by the operation in manipulating the listening keys KK and K which contain the contacts 71, 72 and 73 in the circuit of theresistance coil R.

It will be noted that when these contacts are all closed indicating anidle condition of the operator, that the shunting of SR by R will reducethe resistance effect of SB, and that when all the contacts of thelistening keys above mentioned are opened the removal of this shuntabout the resistance winding SR will restore it to its full resistanceeffect.

In practice I may dispense witheither the resistance winding SR or theresistance coil B, together with its associated key contacts, entirely.But I may as illustrated in this embodiment of my invention, use the twotogether, the one modifying the efiect of the other; the particulararrangement used depending upon the conditions local to the exchange andthe results vdesired to be secured.

We will assume now that another subscriber on the line L such as thesubscriber B initiates a call, and by closing the switchhook contacts 0places his set r across the telephone line conductors which extend bythe cross connecting wires 39 and 40 and the circuit conductors 60 and61, through contacts 56 and 57 to the line relay LRB ofthe line and thesource of current S included in circuit therewith energizes the linerelay, closing its contacts 3 in the circuit of the answering lamp LB,and the concentration lamp CLB in multiple, the circuit being traced asfollows: From the ground pole of the source of current S through thelamps CLB and circuit conductors 4:5 and 37 in multiple with the lampLB, the terminal 13 of the cross connecting rack C, circuit conductor48, contacts 3 of the line relay LRB, and common circuit conductor 55leading through the low resistance winding of the double wound relay tothe circuit conductor 54 and from thence through the winding SR, theinterrupter I and the resistance coil it all in multiple, to thenegative pole of the source of current S. i

It will be seen that under the assumption that the first call has notbeen answered, that there are now two calls on the operators positionand SlX lamps associated with two calling lines are operated, theenergizing circuit or all of the lamps including in common theresistance coil SR which is shunted by the resistance coil R and theintermittently short circuiting interrupter I. The drop in voltageacross the resistance being expressed by the formula voltage equalscurrent times resistance, is thus proportional to the current flowthrough the resistance, and therefore the drop of voltage across theshunting resistance SR is nearly double that caused by the lighting oflampsof one line; and the inclusion of this resistance in'cir- -willoperate her listening key K, with the said connecting circuit breakingthe contacts 72 therein contained andwhich are serially included withthe resistance coil E in the shunting circuit about the terminals of theresistance winding Sit inthe lamp circuit. The elimination of thisresistance coil from about the terminals of the" resistance SR iseffective to increase the common resistance serially included with thelamps of the remaining unanswered calling line, the lamps of theanswered line having been eX- tinguished in the ordinary way by the actof the operators making connection with the line and releasingthe linerelay thereof.

Now, the resistance of the coil B may be roportioned to produce various-efiects. ut I prefer to inake it of aboutthe same resistance as thewinding Slhso that when the operator is attending to a call the eiiectof "the resistance SR is double, that is, the resistance SR will bedouble that of the combined resistance of and R in mul tiple; thereforewith one unanswered calling line and one call being answered theeffect-on the lamps of the remaining unanswered line will be modifiedfrom the eliect which would prevail ii" the operator did not have alisteningkey thrown, the modification being in the direction ofincreased flashing, that is, increased variation in brilliancy. Thisvariation may bea s has been above indicated modified to any suitabledegree by the relative and quantative valucs chosen for the resistancesIt and Uther lines may also lead into the operators position and aportion of a third line is indicated by its cross-connecting Wires 29,30, Sl-and 32, being shown as extending between the set oi terminals l7,18, 19 and 20 on the line side, and theset 5, 6, 7 and Sonthe answeringswitchboard side of the crossconnecting rack, The common circuitconductor-55 in the signaling circuit divides to connect' with the linelamps of all of the lines in thegroup served by the same commonapparatus, and which are preferably those belonging toa given operatorsposition.

it is obvious from. the foregoing description that the system hereindisclosed is not only capable of giving the lamps o'f "a -line ona busypositiona'n indication of the busy condition, but also is capable ofindicating the measure of the busy condition of such a position. i v I pThe concentration sections of the switchboard alsoh'aveoperatorsanswering equipment placed "thereon, and it is the'duty of theoperatorsat such positions'to answer the calls on lines which have theiranswering terminals in busy positions, preference in answering at suchconcentration sections being :given 'to the lines on the position whichby the flashing of the lamps indicate the greatest degree ofover-loading at the home :or answering positions. In this way theseconcentration operators or helping0perators are'enabled'toes'sist thehome operators who are most'in needot'the help.

Y It is obvious that many and extensive departures may bermade from theembodiqmen't illustrated and described herein without departing from thespirit :ofthe invention; This-invention-is in the natureofan improvementover the. invention disclosed in the co-pending application of WilliamS. Paca,.Serial No. 202,748, filed Nov."19th, .1917, wherein marginalrelays are employed to change the characterof the extended signal on theassociated :switchboard whenever a predetermined load has been exceededon the main switchboard. In the 4 ciated signal lamps, and commoncontrolling means quantitatively responsive to the total number ofsignal lamps operated to correspondingly varythe quantitative characterof the signal given by the said lamps. 2 In a telephone system, thecombination of a telephoneswitchboard divided into nor- 'mal answeringand abnormal helping sections, of a plurality of telephone linesterminating at each of the switchboards in multiple connection switches,vof individual signal lamps for each of the lines associated withthe-said switches, and 'colnn'ion'controlling meansquantitatively.responsive to the number of signal lamps operated,quantitatively controlling the said lamps. r

8. In a telephone system, the combination with a telephone switchboarddivided into normal answeringand associated helping 1 ,aav are sections,of a plurality of telephone lines terminating at thenormal answeringsection in terminals of connection switches, of: signal lamps for-eachof the lines associated with the-said'terminals, of multiple terminalsfor each of the lines at the said helping switchboard section,a-resistaneeunit in=the-circuit of all the lamps o-fa group terminatingin the said answering switchboard section and in the circuit of theassociated lamps atthe helping switchboard section, and anintermittently operated shunt for the said frerSlSlIHiIlCG unit, saidintermittently operated 'shuntbeing operated at such a rate as to flashthesa id lamps; a

4. In aitelephone system, the combination with a plurality of telephonelines and a plurality of multiply connected ,:'signal lamps, of acircuit for "said :multiply conwith a plurality of multiply connectedswitchboard lamps, of a resistance unit and a source (if-current in theconnnon-circuit thereof, an intermittent shunt for the said resistanceunit, and -a manual switch for varying thefquantitative value of thesaid resistance unit. v a

'6. In a telephone system, the combination with a pluralityof'telepho'ne lines and signal lamps, ot-a source of current and aresistance unit, an individual switch for each lamp to connect thesamein operative circuit with-said source of current through'saidresistance unit, ;mea-ns, cont-rolled over said telephone line forclosing'said individual switch, and an'intermittently operated shunt forthe said resistance unit, said shuntbein adapted to flashthe said lamps7. In a telephone system, the combination with a plurality of signallamps, of a double wound pilot relay and a) source of current, anindividual switch for each of the said lamps to connect the same inoperative circuit with the said source of current through. both of thewindings ot the said double wound relay, and an intermittently operatedshunt forone ot the said windings,

" 8. In a telephone system, the combination with a plurality'of'signallamps, of'a double wound pilot relay and asource of current, anindividual switch for each of the said lamps to connect the same inoperative circuit with the saidsource of current through both of thewindings of the'saiddouble wound relay, an intermittently operated shuntfor one of the said windings, and a vpilot lamp controlled by anarmature of the-saiddouble woundrela ios 9. In a telephone system, thecombination with a plurality of signal lamps, of a double wound pilotrelay and a source of current, an individual switch for each of the saidlamps to connect the same in operative circuit with the said source or"current through both of the windings of the said double wound relay, anintermittently operated shunt for one of the said windings, and aresistance unit normally connected in operative relation to theintermittently shunted winding of the double wound relay to change thequantitative resistance character thereof, and manual means for removingthe said resistance unit from operative relation to the said winding.

10, In a telephone system, the combination of a plurality of signallamps, a source of current and a resistance unit, an individual switchfor each lamp to connect the same in operative circuit with the saidsource of current through the said resistance unit, an intermittentlyoperated shunt for the said resistance unit, a second resistance unitoperatively associated with the said first-named resistance unit. tovary the character thereof, and a manually operated switch to dissociatethe said second-named resistance unit from said first-named resistanceunit.

11. In a telephone signalling system, of a group of signal lamps, of asecond group of signal lamps each of which is adapted to beinterchangeably connected with the lamp of the first group, of a sourceof current and a resistance unit, an individual switch for each pair ofthe associated lamps to operatively associate the said pair of lampswith the said source of current through the said resistance unit, and anintermittently operated shunt for the said resistance unit, said shuntbeing operated at such a rate as to flash the associated lamps. 12. In atelephone system, the combination with a plurality of telephone linesand a plurality of multiply connected signal lamps, of a resistanceunit, a circuit for said multiply connected lamps including saidresistance unit, a source of current therein, means controlled over atelephone line for closing said circuit, an intermittentlyoperated shuntfor the said resistance unit and switching means to vary the number ofmultiply connected lamps, said shunt being applied to the saidresistance unit at such a rate as to operatively flash the said lamps.

In witness whereof, I hereunto subscribe my7name this 3rd day ofDecember, A. D 191 FRANK M, sLoUeH.

